Spaced helical radiating conductor insulatingly supported along the length of central conductor support



Jan. 18, 1966 KEIJI ENDO ETAL 3,230,540

SPACED HELICAL RADIATING CONDUCTOR INSULATINGLY SUPPORTED ALONG THE LENGTH OF CENTRAL CONDUCTOR SUPPORT Filed June 6, 1962 Fig. 1

Fig. 2

\ELECTROCONDUCT/VE SURFACE INSULA 7E0 F L ANGE 3 INSULA TING E' LE 6 TROCONDUCT/ VE SURFACE 4 RA 0/4 rnva co ,vauc ran INVENTOR-S A's/415.4100! )smeaS/l/am United States Patent SPACED HELICAL RADIATING CONDUCTOR INSULATINGLY SUPPORTED ALONG THE LENGTH OF CENTRAL CONDUCTOR SUP- PORT Keiji Endo and Yoshizo Shibano, Tokyo-to, Japan, as-

signors to Sumitomo Electric Industries, Ltd., Osaka, Japan, a company of Japan Filed June 6, 1962, Ser. No. 200,414 Claims priority, application Japan June 9, 1961 7 Claims. (Cl. 343-874) This invention relates to an improvement on the helical antenna used for the VHF and UHF broadcasting.

The helical antenna of the conventional type comprises a conductor supported with porcelain insulators at several points around a metal pole and coiled helically. The helical antenna of this type is mechanically weak because the conductor is exposed to the atmosphere. Furthermore, as the conductor is supported with porcelain insulators at several points, there not only takes place the electric reflection due to the discontinuation at the supporting points, but also it is found diflicult to maintain a continuously uniform distance between the metal pole and the conductor. It, therefore, has a drawback that these affect its electric properties detrimentally.

The objective of this invention is to supply a helical antenna which is free from this drawback and which has excellent properties both electrically and mechanically, supporting the conductor continuously on the metal pole. It is characterized in that an insulating material which has a conductor buried in it along one of its edges has the other of its edges molded and fixed in a continuous helical form to the circumference of a metal pole.

We will explain this invention with reference to the drawings illustrating its application.

FIGURE 1 is a frontal view of the helical antenna of continuous support type of this invention.

FIGURE 2 is an example of a sectional part of the antenna of FIGURE 1.

In the drawings, 1 denotes a pole the surface of which is electro-conductive. It may be a metallic pole, a pole of a dielectric material whose surface has been made electro-conductive by closely covering it with metal foil, or a pole of a dielectric material on which an electroconductive layer has been formed by vaporization plating. 2 denotes a belt-form body of a uniform width which is made of an insulating material. 3 denotes one edge of the belt-form body, and a conductor 4 is buried along this edge. 5 denotes the other edge of the aforementioned belt-form body 2. This part is molded and fixed helically and continuously around the circumference of the aforementioned metal pole. It is necessary that the insulating material to make the belt-form body 2 is not only excellent in mechanical strength, resistance to heat and resistance to weather, but also has excellent electric properties. Such plastics as polyester, polyethylene, etc., are suitable for use as an insulating material satisfying these requirements. However, the best-suited material is obtained by reinforcing such plastics with glass fiber or the like.

As stated above, the helical antenna of this invention is of the structure of continuous supporting, so that it does not involve the discontinuation at the supporting points of antenna conductor. Furthermore, the distance between the pole and the conductor is continuously uniform. It therefore has highly excellent electric properties, which make it suitable for use for VHF broadcast and UHF broadcast.

Moreover, as the antenna conductor is buried in an insulating material, it does not get corroded and it has a great mechanical strength.

We claim:

1. A helical antenna of continuous support type which is characterized in that a continuous flange of insulating material having a conductor buried in it along one of its edges, the other of its edges fixed in a continuous helical form around the circumference of a circular surface of electro-conductive material to support said conductor at a uniform depth from said circular surface.

2. A helical antenna of continuous support type described in claim 1, which is characterized in that said circular surface consists of a metallic material.

3. A helical antenna of continuous support type described in claim 1, which is characterized in that said circular surface consists of a dielectric material over the surface of which said electroconductive material is formed as a metal layer.

4. A helical antenna of continuous support type described in claim 1, which is characterized in that said flange of insulating material is made of a plastic material.

5. A helical antenna of continuous support type described in claim 1, which is characterized in that said flange of insulating material is made of a plastic material reinforced with glass fiber.

6. A helical antenna of continuous support type described in claim 1, which is characterized in that said circular surface consists of a solid metal pole.

7. A helical antenna having a central conductor and a radiating conductor with spaced helical turns insulatingly supported on said central conductor wherein said central conductor is a full continuous circular conductive surface many times larger in circumference than said radiating conductor, an outwardly extending continuously helical flange of insulating material mounted on the circular conductive surface of said central conductor, an

edge of insulating material extending along said flange at a uniform distance from said continuous circular conductive surface, and a helical radiating conductor embedded in said edge and held at a uniform distance from said continuous circular conductive surface to shield said radiating conductor from the ambient elements and eliminate discontinuation of electric reflection at specific supporting points.

References Cited by the Examiner UNITED STATES PATENTS 2,681,412 6/1954 Webster 343-873 3,066,295 11/1962 Krause 343-895 3,098,230 7/1963 Nickerson 343- 873 HERMAN KARL SAALBACH, Primary Examiner. 

1. A HELICAL ANTENNA OF CONTINUOUS SUPPORT TYPE WHICH IS CHARACTERIZED IN THAT A CONTINUOUS FLANGE OF INSULATING MATERIAL HAVING A CONDUCTOR BURIED IN IT ALONG ONE OF ITS EDGES, THE OTHER OF ITS EDGES FIXED IN A CONTINUOUS HELICAL FORM AROUND THE CIRCUMFERENCE OF A CIRCULAR SURFACE OF ELECTRO-CONDUCTIVE MATERIAL TO SUPPORT SAID CONDUCTOR AT A UNIFORM DEPTH FROM SAID CIRCULAR SURFACE. 